When working with CSS, Sass is really cool. When working with Sass, Compass is really, really, really cool.
What is Compass?
(per it’s website:)
Sass is an extension of CSS3 which adds nested rules, variables, mixins, selector inheritance, and more. Sass generates well formatted CSS and makes your stylesheets easier to organize and maintain.
Here is all the Documentation on Compass you’ll need to get started.